Add ParsedPayload::video_header() accessor.

Preparation CL to remove RTPTypeHeader.

Bug: none
Change-Id: I695acf20082b94744a2f6c7692f1b2128932cd79
Reviewed-on: https://webrtc-review.googlesource.com/86132
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23835}
diff --git a/modules/video_coding/packet.cc b/modules/video_coding/packet.cc
index 7db566a..e4e1ca4 100644
--- a/modules/video_coding/packet.cc
+++ b/modules/video_coding/packet.cc
@@ -50,20 +50,21 @@
       timesNacked(-1),
       frameType(rtpHeader.frameType),
       codec(kVideoCodecUnknown),
-      is_first_packet_in_frame(rtpHeader.type.Video.is_first_packet_in_frame),
+      is_first_packet_in_frame(
+          rtpHeader.video_header().is_first_packet_in_frame),
       completeNALU(kNaluComplete),
       insertStartCode(false),
-      width(rtpHeader.type.Video.width),
-      height(rtpHeader.type.Video.height),
-      video_header(rtpHeader.type.Video) {
-  CopyCodecSpecifics(rtpHeader.type.Video);
+      width(rtpHeader.video_header().width),
+      height(rtpHeader.video_header().height),
+      video_header(rtpHeader.video_header()) {
+  CopyCodecSpecifics(rtpHeader.video_header());
 
   if (markerBit) {
-    video_header.rotation = rtpHeader.type.Video.rotation;
+    video_header.rotation = rtpHeader.video_header().rotation;
   }
   // Playout decisions are made entirely based on first packet in a frame.
   if (is_first_packet_in_frame) {
-    video_header.playout_delay = rtpHeader.type.Video.playout_delay;
+    video_header.playout_delay = rtpHeader.video_header().playout_delay;
   } else {
     video_header.playout_delay = {-1, -1};
   }